1. Field of the Invention
This invention relates to apparatus for connecting a rotary member to a stationary or rotary member by means of a hydrualically operable friction coupling.
More particularly, this invention relates to a clutch or brake mechanism wherein the connection is made by two opposing annular diaphragm actuators hydraulically clamping an annular connecting member situated between the diaphragm actuators.
The invention is exemplified by a diaphragm disc brake device operated by a dual piston hydraulic braking cylinder.
2. Description of the Prior Art
A revoluable work table has been illustrated and described in U.S. Pat. No. 2,959,988 issued to Clarence D. Abrams Nov. 15, 1960. The work table may be clamped in place in any position by means of opposing diaphragm acutators hydraulically operated to clamp an annular member fixed to the table. The structure is not designed for braking nor used for that purpose, but only for clamping. U.S. Pat. No. 1,909,744, issued May 16, 1933 to R. E. Berg discloses a brake which is operated hydraulically to expand a diaphragm between two toothed brake shoes. The diaphragm and shoes are annular and when fluid pressure is applied the brake shoes act on both sides of the enclosing drum. A dual-cylinder hydraulic actuator for automotive brake systems is disclosed by G. T. Randol in U.S. Pat. No. 3,172,265, issued Mar. 9, 1965. The two pistons are not differentially designed but have an equalizer or compensator to assure that equal pressure is provided to each of the front and rear systems respectively.
No system has been found and none is known wherein a high speed rotating member is coupled to another member rotatable or stationary, by means of two opposing diaphragm operated braking members being clamped to a central disc attached to the rotating member.
Also, no dual acting fluid brake cylinder has been found which delivers a first large volume surge followed by a small volume, high pressure, braking force.